E x  estwing



E. o. ESTWING mlmo Dec. 20, 1927,

amp 'IQQL Original Film; July 17. 1924 Reissued Dec. 20, 1927.

UNITED STATES;

ERNEST o. nsr'wmd, or ROCKFORD, ILLINoIsAssIoNoR 'ro issrwme MANUFACTUR- me coMrANY, nd, ornooxronn, ILLINOIS, A com'oaa'rron or ILLINOIS.

HAND TOOL.

I Original No. 1,578,502, dated March [30, 1926, Serial No. 726,433, filed July 17, 1924. Application 1' 1- reissue filed October 16, 1926. Serial 'No. 142,143.

This invention relates to hand striking tools and implements and; has more part1c-. lar reference to axes, hammers and hatchets.

The primary purpose of the invention is tO'PIOVldG an improved hand tool, such for example .as an axe, hammer or hatchet, in which the'head and handle are drop forged in one piece and so shaped and treated that maximum strength is obtained with minimum weight and material and the tool is well balanced and substantially unbreakable.

By this I mean that it is unbreakable when used 'in the manner and for thepurposes intended for tools of this kind. By making the handle and head in one piece the many objections to, the conventional construction employing fastening means or devices of some sort for securing the head to the handle are entirely obviated. Moreover, according to my invention thehandle is reduced substantially from end to end to a comparatively narrow elongated cross-sect on the major axis of which is parallel with that of the head. This reduced cross-section throws the center of gravity in the head or close thereto, according to the style of the tool, which gives a highly desirable balance. This balanceenables more eflicient use of the tool because the greatest weight being in the head enables the greatest degree of manual effort to be transmitted in the blow.

With such a tool there is the least lost effort 1 due to the balance of handle and head and consequently. the tool is less tiring to use and the strokesare more eifective than with the conventional style of tool. The foregoing results are attained to better advantage when the handle is tapered in thickness gradually from the head to itsremote end, thus further throwing the center of gravity close to the head andproviding' the greatest strength adj acerit thereto, at'which point the greatest strain and stress occurs from the efiects of the blow, Another ad-- vantage resulting from a tool shaped as described is that it may bev used very efiec tively as a pry for splitting wood and in some instances as a crow bar by sidew'ise ressu'ref on the handle afterthe blade hasv "een inserted between or driven into the parts to be separated. In order to fill out the hand grip suitable scales or grips are riveted or otherwise secured to the sides of the handle. I

- The foregoing features of construction are made possible in a commercially practical tool by reason of the method employed in manufacturing it. According to my inventiontheaxe, hammer or hatchet is formed or shaped in one piece by drop-forging. The

forgings or tool blanks are then normalized to'reduc'e internal strain in the structure or to establish equilibrium ofthe'constituentsb The toolblanks. are then. annealed for machineability and following this are hardened by heat treatment as.will be explained more fully hereinafter. Other objects and attendant advantages w ll be appreciated by those skilled in this art as the invention becomes better understood by'reference to the following description when considered in connection with the accompanying drawing, in which Figure 1 is a side elevation of a scouting or outdoor axe or hatchet, embodying my invention;

hatchet;

F gs. 3,4, 5 6 are sections taken on the'lines"3 3, 4 4, 5- 5 and 6-6, respectively, of Fig. 1;

Fig. 2 is an end view of the head of said Fig. 7 is a side elevation of a carpenters hatchet embodying my invention; Fig. 8- is an end view of the head shown 1n Fig. 7; and

Fig. 9 is a section taken on the line 9-9. of Fig. 7. c

My invention is applicable to any hand tool having a striking head suchi'or' example as an axe,.hammer, or hatchet; conse quently the following description of the invention except in so far as it relates to the specific shape characterizing any one tool' from another, is applicable to all tools of.

this type.

Considering first the structural characteristics common to these tools, my invention provides a metal head and ahandle shank in cnepiece. The head, designated generally by 11, may be of any suitable shape, such as an axe" head, hammerhead or hatchet head, exceptthat according to my invention the head may be comparatively [narrow for efiective cleavage because no eye forthe handle or helve is necessary. This is especially desirable in carpenters ,hatchets as shownin Fig.8, and is alsodesirable inscouting or outdoor hatchets as shown in Fig. 2. The handle shank consists of a neck 12* and a grip-carryingportion 1-2. At the front end of the grip-carrying portion are shoulders 12. The neck is made thin in a plane transverse to the plane of the head, its mean thickness being approximately one-third of its width in the plane of the head. This reduces Wind resistance to a minimum and gives max mum str ngth 1n the plane 1n which most stresses occur when using the tool in striking. The greatest cross-sectional area is at the juncture of the head and handle, as shown in Figs. 3 and 6, so that the greatest strengthis at the point of greatest stress. The-handle tapers in thickness toward its outer end and is therefore of agradually reducing cross-section as clearly shown in said ures 3 to 5. inclusive. This reduced cross-sec ion although not necessar ly'tapered, is an essential feature of my invent-ion for the reason thatit throws tne center of gravity forward, to or in pro'ximity to -the head with consequent 'advantages as described above and for the further reason that the reduction in sectional area iscarried out in a way so that'it provides the greatest. requisite strength with the least amount ofmetal. The reduced cross-section is made possible by the method of'manufact'ure hereinafter described and is, therefore,

. dependent on such method in so far as the production of a commercially practical and saleable tool is concerned.

Wooden scales or grips 13 are secured to thesides of the grip-carrying portion 12 of the handle shank by suitable means such as rivets 14. The grips may, however, be of any siutable orpreferred material which is light in Weight and durable. Q

It will be observed from the foregoing that my invention contemplates the manufacture of a striking tool byforming and shaping the striking head and handle shank 'by forging operations to produce an integral, one-piece'tool. The ,tool' is forged into a novel shape characterized by its c'ompara-- tively flat, narrow handle shank which com gated in a plane parallel with the major axis of the striking head and is further reduced or tapered longitudinal-lyat both sides gradually from the striking head to the opposite end. By reason of this narrow cross-section usual strength in the handle an tion to prying,

less metal is employed in the handle which, consequently, is of less weight than in any prior striking tool having a head and a handle shank in one piece, whether it be in an axe, hatchet, hammer or the like. This is accomplished without impairing the shape and usefulness of the tool; and moreover, it enables a better distribution of the metal for strength and balance for the reason that the handle cross-section is comparatively flat and narrow and elongated in the lane of the stresses incident to striking b ows,

'and also because the necessary weight in the head will be contributed to by the thicker transverse sectionof theshank portion adjacent thereto. The only exception to the above-mentioned reduction in transverse might be used. It will be observed that-in actual practice the neckand grip-carrying portion are thinner or narrower in trans- ;verse cross-section than shown in the drawings, in proportion .to the size of each tool shown. That is, the drawings show the neck and grip-carrying portion cross-sections thicker in order to more clearly illustrate the longitudinal transverse taper.

For some embodiments of the invention it is desirable that the forged tool be heat-' treated to remove all strains incident to the forging operations and to uneven cooling of the shaped tool, to refine the microstructure characteristicof the metal, and to increase the tensile strength, raise the elastic limit and reduce ductility. By combining the above-mentioned characteristics of shape and definite physical properties by reason of this method of manufacture I obtain a new 're- .sult, namely, a hand striking. tool which is substantially unbreakable for the purposes intended and has less material in the handle and better balance and feel than any prior one-piece metal tool, so far as I am aware.

Furthermore, a striking. tool made in accordance with my invention is far more useful than prior tools of this kind, that is, it

can be used for more purposes and can be sulnected to harder ,use without damaging the tool. This is due primaril to the un-.

splitting and pulling beyond the range .oftools of this character on the market. I

The method of manufacture is as follows: A high carbon steel should be used, preferably one having the following chemical its adapta composition: carbon, .70.80.%; manganese, .60.80%; sulphur, .03.04%; and silicon, .09-.20%. In addition to complying with the foregoing analysis, the steel must be free from nonmetallic inclusions when examined under the microscope. The tool will be formed and shaped by drop-forging operations, it being noted that the forging temperaturesshould be closely observed and kept within the range of from 1900 to 2100 F. The forgings are then normalized to established equilibrium by heating to 1550 F. and quenching in oil. The next step is to anneal for machineability, that is, for rough grinding and drilling the rivet holes, obtaining a Brinell hardness of 190200. Following this the tool blanks will be hardened by heat treatment. The first step is to heat the blanks to 1450 F., then quench in mineral oil, thus obtaining a martensitic condition on the cutting edge and a troosti'tolnartensitic condition in the body and handle. The blanks will then be drawn at 406 F. in oil, whereby the cutting edge is converted to troostite-martensite condltion and the handle to sorbotroostite, after which the edge may be ground and the tool finished as by applying the handle grips, polishing, etc. This gives the most desirable physical structure for a tool of this kind and makes possible the use of the reduced cross section in the handle above described.

By reason of the foregoing method of manufacture a high grade tool may be produced and sold at a reasonable price. Furthermore, the finished product has superior qualities because there is no danger or trouble incidental to the head loosening and the handle is unbreakable when put to the uses intended for tools of this kind. As a result of said method the physical properties of the steel after it has been normalized and annealed are approximately tensile strength 120,000 lbs. per square inch, yield point 90,000 lbs. per square inch, reduction of area 20% and elongation 15%; and after the heat treatment operations approximately the following hysical properties areobtained in the finis ed tool: tensile strength 180,000 lbs. per square inch, yield point 150,000 lbs. per square inch, reduction of area 5% and elongation 5%.

, tools While the foregoing describes a preferred method of practicing my invention, the particular steps taken and the examples showing proportions used are merely for purpose of illustration. It should therefore, be understood that in manufacturing striking in accordance with my invention changes may be made in'details of construction, as for example, when applying the invention to the manufacture of dilferent tools, such asaxes, hatchets, hammers and the like, also that any suitable or equivalent steps and operations might be employed for securing the desired physical properties in v the metal of the finished tool, Without departing from the spirit and scope of the in.- vention as expressed in the appended claims, in which- I claim as my invention:

1. A hand striking tool having a forged one-piece striking head and handle shank, said shank comprising a neck and a grip carrying portion, the mean thickness of the neck in a plane transverse to the plane of the head being less than one-third of its width in the plane of the head, and a grip on the grip-carrying portion, the wei ht of the handle as a whole being less than t at of the head, and the handle shank having transverse shoulders at the front end of the gripcarrying portion.

2. A hand striking tool having a forged one-piece striking head and handle shank, said shank comprising a neck and a gripcarrying portion, the mean thickness of the neck in a plane transverse to the plane of the head being less than one-third of its width in the plane of the head, said shank being heattreated to permit maximum reduction in thickness.

3. A hand striking tool having a steel head and a handle connected thereto, said handle comprising a-steel neck'and a grip, the mean thickness of said neck in a plane transverse to the, plane of the head being less than one-third of its width in the plane of the head and the weight of theentire handle being a small proportion of the weight of the Whole tool.

In't-estimony whereof, I have hereunto affixed my signature.

ERNEST O. ESTWING. 

